In a statement released shortly after the midnight ET early Friday, China’s Ministry of Commerce called the new tariffs – which beginning at 12:01 a.m. ET imposed a 25% duty on $US34 billion worth of Chinese exports to the US – “typical trade bullying” and warned that retaliation would be swift.

The Commerce Ministry said the US had violated World Trade Organisation rules and “launched the largest trade war in economic history.”

To comply with the WTO, which guides global trade, Trump has argued the tariffs are necessary for US national security, saying they are the result of an investigation by the administration into theft of US intellectual property by Chinese firms and the Chinese government. The tariffs were originally announced in March, but a series of procedural delays and trade negotiations pushed back implementation to Friday.

The Chinese government also hit back with tariffs on $US34 billion worth of imports from the US almost immediately. Lu Kang, a spokesperson for the Ministry of Commerce, told reporters that the tariffs went into effect “immediately after the implementation of the US tariffs.” In their statement, the Ministry of Commerce said that while China had not “fired the first shot” in the trade war, the country would be “forced” to retaliate with equal measures.

The back-and-forth trade battle between the world’s two largest economies is likely to damage the US economy, according to trade experts. That conclusion was not lost on the Chinese Commerce Ministry, which said the tariffs would “damage the interests” of American businesses and people.

The two sides’ tariffs each focus on particular industries in an attempt to make the duties as painful as possible. Trump’s tariffs center on industrial goods and technology, a move designed to take aim at Chinese President Xi Jinping’s heralded Made in China 2025 plan.